Q: How do I “overwinter” or get my pond plants ready for the winter?
– Maryann in Wisconsin

A: If you live in cooler climates – even those that don’t dip too far below freezing – it’s almost time to prepare your plants for winter. Each type of aquatic plant needs to be cared for in a different way, but the most important factor to remember is that the roots of your plants must not come into contact with ice or freezing temperatures. If they do, they simply won’t survive.

Keeping in mind regional variances, here’s how to keep your aquatic plants healthy, happy and ready to bloom again next spring:

1. First, remove any dead leaves from the plants growing around your pond. Give bog plants, like irises and taro, a good inspection and clip off any unhealthy growth, spent leaves or blooms. You want your plants to go into winter as healthy as possible so they emerge strong and stout in the spring.2. Next, pull on your waders and tend to your hardy water lilies. Pull them out of your pond and trim them to about 3 inches above the root system. When you’re done, move the pots or baskets to 18 inches deep or lower, where they’ll be warm and safe from winter frost.3. If you have tropical and floating aquatic plants, like tropical lilies or lotus, it’s easiest to treat them as annuals: Remove them from your pond and mulch the soil and root balls. In most climates, they won’t survive the cold winter conditions. You can try to overwinter them in your shed or garage, but it can be difficult, as many of the tropical varieties require temperatures above 60 degrees Fahrenheit and strong light to survive.4. Treat floating aquatic plants, like water hyacinth and lettuce, as annuals, too. Fortunately, they’re relatively inexpensive to replace year after year.5. For hardy lotus, trim back the foliage after they have gone dormant and turned brown. Don’t trim them while the plant and leaves are still green, as it can cause it to be susceptible to diseases that creep in through the hollow stems. In cooler climates, move your plants to a cool, but frost-free area in your yard or the bottom of your pond, along with your water lilies.

Depending on the size of your pond and the number of plants you have, this winterizing chore shouldn’t take longer than an afternoon, but you’ll be rewarded in the spring with healthy growth that will once again beautify your outdoor living space!

POND TALK: Have you ever overwintered your tropical water lilies indoors? How did you do it?

7 Responses

I live in Montana and have about a three thousand gallon pond with fish and plants. The cattails and other grasses I dug up from a nearby lake….so do I still have to put these native plants in deeper water in my pond if they were dug up off the shoreline in less than a foot of water which is the depth they are placed at now ?

Cattails are really hardy and usually will do just fine, but understand that their root systems are deep underneath the pond/lake, unlike a water garden where the roots can only go as far as the liner. This means in a pond/lake the roots won’t freeze, but in a water garden, it is more likely for them to freeze.

Tropical water lillies need to come inside for areas with freezing temps. or treat them as annuals whereas the hardy lillies can stay in the bottom of a pond just fine as long as they don’t freeze. I do cut them back just so the leaves don’t rot & make the water for the fish any more toxic then it already is.

We got a Wal-Mart package of 3 water lilies for $10 about 3 years ago and we do absolutely nothing to them. I didn’t even know you should cut them back. I keep the yellowed leaves pinched off throughout the summer but haven’t cut them back for the winter. They sit in the bottom of 2 preformed ponds and the ponds are both, if brimming full, just barely 18″ deep. We keep a defroster going for our 15-cent gold fish in each pond throughout the winter and the lilies have come back for two years and this was their best year ever! Maybe they thrive on neglect?

To overwinter those expensive water hyacinth’s, ($5.00 a pop) I place about 25 of them into “under the bed” plastic storage bins in lots of water so they can float. I keep “shop” lights on a few inches above them all winter long. My basement temps are about 55-60 degrees. I can usually salvage about 15-20 plants to put into my 1900 gal. pond. Every penny counts in this economy!

How should I overwinter a floating “sensitive plant”. Where I bought it the person looked up in some book that it should be brought inside and kept in water. Am wondering if it should be kept in moving water? Also, the pH was to be 7.0 I think but that shouldn’t be a problem. Any ideas you have will be appreciated. I live in Northern Virginia.
Pat